Mattress foundation



FIG. 1 is a perspective view of a mattress foundation having diagonal slats according to my new design;

FIG. 2 is a top view of the mattress foundation;

FIG. 3 is an end view of the mattress foundation, the opposite end being a mirror image thereof;

FIG. 4 is a side view of the mattress foundation, the opposite side being a mirror image thereof; and,

FIG. 5 is a bottom view of the mattress foundation.

The dotted lines are for illustrative purposes and form no part of the claimed design. 

CLAIM The ornamental design for a mattress foundation, as shown and described. 